Selector valve and use thereof in a fractionation system

ABSTRACT

A five ported selector valve having an inlet, two outlet and two vent ports in which a ball is moved therein to alternately place the inlet port in fluid flow communication with each of the outlet ports in response to stopping and restarting of fluid flow through the inlet port. The outlet port not connected to the inlet port is in fluid flow communication with its respective vent port. The valve is particularly suited for reversing flow in a dual tower adsorption system. A three ported valve in which fluid is alternately directed from an inlet port to one of two outlet ports is also disclosed.

ilited States Patent; 1

Kauer, Jr. et al.

[ Get. 30, 1973 SELECTOR VALVE AND USE THEREOF IN A FRACTIONATION SYSTEM[73] Assignee: Air Techniques Incorporated, New Hyde Park, N.Y.

[22] Filed: Apr. 1, 19711 21 Appl. No.: 130,271

[56] References Cited UNITED STATES PATENTS Struve 137/112 Hamish et al.137/112 X 3,447,556 6/1969 Howeth 137/112 3,463,389 8/1969 Mott 137/1 19X 3,614,965 10/1971 Metivier 137/119 Primary ExaminerAlan CohanAttorney-Mam & Hangarathis [57] ABSTRACT A five ported selector valvehaving an inlet, two outlet and two vent ports in which a ball is movedtherein to alternately place the inlet port in fluid flow communicationwith each of the outlet ports in response to stopping and restarting 0ffluid flow through the inlet port. The outlet port not connected to theinlet port is in fluid flow communication with its respective vent port.The valve is particularly suited for reversing flow in a dual toweradsorption system. A three ported valve in which fluid is alternatelydirected from an inlet port to one of two outlet ports is alsodisclosed.

5 Claims, 5 Drawing Figures PATENTEDUCT 3 0 I975 3.768.500 SHEET 10F 314 f 7/ 72 T /5 55 39 yII/l/l/IIIA, Q 5; W /2 73 74 A4, flu

Fig. l. 27 32 ,I I v INVENTORS George C. Kuuer, Jr. Louis E. BrooksATTORNEYS PATENIElJncr 30 1915 3.768500 SHEET 2 (IF 3 a I I I v I I w mToRs George C. Kou Louis E. Brooks BY 772mm 8(W PATENIEDucr 30 1975 3.768.500 SHEET 3 BF 3 INVENTORS George C. Kouer, Jr. Louis E. BrooksATTORNEYS SELECTOR VALVE AND USE THEREOF IN A FRACTIONATION SYSTJEM Thisinvention relates to the fractionation, by adsorption, of a compressedgas, and in particular, to the fractionation of a compressed gas by theuse of dual adsorption chambers. This invention also relates to a newand improved valve for alternately directing flow from an inlet port toone of two outlet ports. This invention further relates to a new andimproved valve which may be employed in a system effecting adsorption indual chambers.

The use of two adsorption chambers for fractionating a gas in which oneadsorption chamber is employed for adsorbing a component of a gaseousmixture while the other chamber is regenerated by passing a portion ofthe unadsorbed gas therethrough at a reduced pressure,.

is known in the art, and is exemplified by US. Pat. No.

2,944,627, granted July 12, 1960. In such a system, compressed gas isdirected through one adsorption chamber to effect adsorption of acomponent thereof, with a major portion of the unadsorbed gas beingpassed directly to utilization equipment and a minor portion of theunadsorbed gas being passed through a pressure reducing flow controllerto a second chamber which has previously been employed for adsorption.The unadsorbed portion of the gas is passed through the adsorbent in thesecond chamber to effect desorption of the adsorbed component and thegas containing the desorbed component is then vented to atmosphere.

The apparatus is provided with piping and valves to alternately connectthe two chambers to adsorption and desorption and the valves aregenerally solenoid operated valves which are activated by a cycle timingdevice which maintains each chamber, on each portion of the cycle, for ashort period of time; for example, from 30-80 seconds.

The prior art dual tower systems havenumerous disadvantages. Thus, forexample, the desorption operation is continuous,-even if the system isnot using the unadsorbed portion of the gas, with the compressor runningto meet desorption demands. In addition, such systems do not include astorage tank and in order to keep such systems operating under allprobable load conditions,'the regeneration must be designed for themaximum probable load condition, resulting in considerable waste in thatflow required for regeneration is excessive at all conditions, exceptmaximum load. Furthermore, such systems depend on a combination of avalve and timer to change the cycle which is not generally reliable.

Accordingly, an object of this invention is to provide for desorbing ofa component of a gas in a manner which avoids the aforementioneddisadvantages.

Another object of this invention is to provide for effecting improvedadsorption and desorption in dual adsorption chambers.

A further object of the invention is to provide for improved switchingfrom adsorption to desorption in a dual adsorption chamber operation.

Still another object of this invention is to provide for a new andimproved valve.

Still another object of the invention is to provide a new and improvedvalve for alternating flow from an inlet port to one of two outletports.

Yet a further object of this invention is to provide for a new andimproved valve which is particularly suitable for changing theadsorption and regeneration cycles in a dual tower adsorption system.

These and other objects of the invention should be more readily apparentfrom reading the following detailed description thereof with referenceto the accompanying drawings, wherein:

FIG. I is an elevational view, in cross-section, of a preferredembodiment of the valve of the invention in a first operating position;

FIG. 2 is an elevational view, in cross-section, of the embodiment ofFIG. I in a second operating position;

FIG. 3 is an elevational view, in cross-section, of the embodiment ofFIG. I in a third operating position;

FIG. 4 is a simplified schematic representation of a dual toweradsoption system incorporating the valve embodiment illustrated in FIG.1; and

FIG. 5 is an elevational view, in cross-section, of another preferredembodiment of the valve of the present invention.

The objects of this invention are broadly accomplished, in one aspect,by providing for adsorbing of a component of a compressed gas by meansof a suitable adsorbent in which adsorption of the component by theadsorbent, and subsequent regeneration of the adsorbent by desorption ofthe component, is effected when the compressor is in operation and theswitching of the adsorbent from the adsorption of an overall cycle tothe desorption portion of the overall cycle and vice versa, iscontrolled by a selector valve which changes flow in response todeactivation and activation of the compressor.

More particularly, a compressed gaseous mixture is passed through aselector valve to a first adsorbent bed to effect adsorption of onecomponent thereof and a first unadsorbed portion of the gas is passed toa storage tank for subsequent utilization. A second unadsorbed portionof the gas is passed, at a lower pressure, through a second adsorbentbed in which the one component has previously been adsorbed to desorbthe one component therefrom and thereby regenerate the bed forsubsequent adsorption and the gas, containing the desorbed component ispassed through the selector valve to the atmosphere. The adsorption inthe first bed and the desorption in the second bed is continued untilapredetermined maximum pressure is obtained in the storage tank, atwhich time, the compressor is deactivated, and the elements of theselector valve are automatically moved in response to the deactivationof the compressor to a position in which upon reactivation of thecompressor the valve elements are moved to a position in which the flowpath is reversed to effect adsorption in the second bed and desorptionin the first bed. The compressor is reactivated upon the pressure in thestorage tank reaching a predetermined minimum, and adsorption iseffected in the second bed and desorption in the first bed until thepressure in the storage tank again rises to a predetermined maximum,thereby deactivating the compressor and resetting the valve elements ofthe selector valve to a position in which reactivation of the compressormoves the valve elements to direct the gas flow to effect adsorption inthe first bed and desorption in the second bed. Thus, the adsorption anddesorption is effected only when the compressor is in operation and thefrequency and length of the overall cycle is a function of the amount ofdesorbed gas required by the utilization system.

outlet ports and each of the outlet ports is in fluid flowcommunicationwith a respective vent port. The valve is provided with a flow controlmeans which alternately directs flow through the valve from the inletport to one of the outlet ports while simultaneously directing flow fromthe other outlet port through its respective vent port. The flow controlmeans alternates the flow from the inlet port to the two outlet ports inresponse to stopping and restarting of flow through the inlet port.

Still more particularly, a pair of flow passages, each connected at oneend to the inlet port and intersecting at their other ends, areconnected, at their intersecting ends, to one vent port and one outletport through a third flow passage and to the other vent port and theother outlet port through a fourth flow passage. The one vent port andthe one outlet port are connected to each other through the third flowpassage and the other vent port and the other outlet port are connectedto each other through the fourth flow passage.

A first closure means, preferably in the form of a ball, is movablypositioned in the intersecting flow passages, and is moved in responseto and by fluid introduced into the inlet port to alternately closecommunication between the intersecting passages and the third flowpassage and the intersecting passages and the fourth flow passage. Thethird and fourth flow passages are each provided with a closure member,preferably in the form of a ball, which is movable in the passage inresponse to and by fluid flowing therethrough from the inlet port. Inthe absence offluid flow through the inlet port, the closure members arepositioned in each of the third and fourth flow passages at a positionwhereby fluid can flow therethrough between the vent and outlet ports.In response to fluid flow through the inlet port, the first closuremember prevents fluid flow to either the third or fourth flow passagefrom the intersecting flow passages and the fluid flow through one ofthe third and fourth flow passages movesjts closure member to a positionwhich closes the vent port and opens fluid flow communication betweenthe outlet port and the intersecting passages, whereby fluid flows fromthe inlet port to one of the outlet ports. The closure member in the oneof the third or fourth flow passages which does not experience fluidflow from the intersecting passages remains in its previous position,thereby maintaining the fluid flow communication between the vent andoutlet ports. I

The selector valve, h'ereinabove described, is employed in a dual toweradsorption system by connecting the inlet port to a compressor, oneoutlet port to one adsorption tower and the other outlet port to asecond adsorption tower. During periods when the compressor isdeactivated both towers are connected to the atmosphere through therespective outlet and vent ports of the valve. Upon activation of thecompressor, the introduction of fluid into the inlet port of the valveopens fluid flow communication between the inlet port and one outletport, whereby compressed gas" is passed to one adsorption tower andmaintains fluid flow communication between the second outlet port andits respective vent port, whereby regeneration gas can flow from theother adsoprtion tower to the atmosphere. Upon stopping and reactivationof the compressor, the fluid flow is reversed in that the inlet port isnow in fluid flow communication with the second outlet port, wherebycompressed gas flows'to the other adsorption tower and the one outletport is in fluid flow communication with its respective vent port,whereby regeneration gas can flow from the one tower to the atmosphere.

The objects of this invention are also accomplished by providing a threeported valve having an inlet port and two outlet ports each connected tothe inlet port. The valve is provided with a flow control means which ismovable by and in response to fluid introduced into the inlet port, saidflow control means alternately directing the flow from the inlet port tothe first outlet port and from the inlet port to the second outlet portin response to stopping and restarting of flow through the inlet port.More particularly, the valve is provided with a first flow passagehaving a first end connected to the inlet port and the second end to thefirst outlet port, and a second flow passage having a first endconnected to the inlet port and the second end to the second outletport, the flow passages intersecting adjacent their second ends. Amovable closure member, preferably in the form of a ball is movablewithin and between the intersecting flow passages. Upon being positionedin the first flow passage, the closure member is moved by fluidintroduced into the inlet port to the second end of the first flowpassage to close the first outlet port, whereby fluid flows from theinlet port to the second outlet port. Upon stopping of fluidintroduction into the inlet port, the closure member falls by gravityinto the second flow passage, and upon restarting introduction of fluidinto the inlet port, the closure member is moved to the second end ofthe second flow passage to close the second outlet port, whereby fluidflows from the inlet port to the first outlet port. Upon stopping theintroduction of fluid into the inlet port, the closure member falls bygravity into the first flow passage.

The invention will be further described with reference to preferredembodiments thereof illustrated in the accompanying drawings, but it isto be understood that the scope of the invention is not to be limitedthereby.

Referring to FIG. 1, a valve body 10 includes an inlet port 11, a firstoutlet port 12, a second outlet port 13, a first vent port 14 and asecond vent port 15. An inlet passage 16, defined by horizontal bore 17,extends inwardly through through valve body 10 from the inlet port 11and terminates within the valve body 10. i

A flow passage 21, defined by angular cylindrical bore 22 having anupper reduced portion 23, connected at its lower end to inlet passage 16through a vertical cylindrical bore 24, extends angularly upwardly awayfrom the inlet port 11, and a flow passage 25, defined by angularcylindrical bore 26 having an' upper reduced portion 27, connected atits lower end to inlet passage 16 through a vertical cylindrical bore28, longitudinally spaced from vertical bore 24, extends angularlyupwardly toward the inlet port 1 l, with the bores 22 and 26intersecting at the upper ends thereof. The bores 22 and 26 haveidentical diameters and a movable closure member, in the form of a ball31, having a diameter approximating, but slightly less than the diameterof the cylindrical bores 22 and 26, is movably positioned for movementwithin the bores 22 and 26 in response to fluid flow therethrough toalternately seat against the shoulder 32 formed between bore 22 and itsreduced portion 23, and the shoulder 33 formed between bore 26 and itsreduced portion 27.

The various dimensions of the bores 22 and 26 and the ball 31 arecoordinated in a manner such that the center of gravity of the ball 31,in the position in which ball 31 is seated against shoulder 32, ispositioned so that gravity causes the ball 31 to fall into bore 26 uponstopping of fluid flow through the inlet port 1 1, and the center ofgravity of the ball 31, in the position in which the ball 31 is seatedagainst shoulder 33, is positioned so that gravity causes the ball 31 tofall into bore 22 upon stopping of fluid flow through the inlet port 11.

A flow passage 35 defined by a vertical cylindrical bore 36 having anunaligned enlarged upper portion 37 and an aligned enlarged lowerportion 38 is connected at its upper portion with the vent port 15through reduced aligned bore 39. A horizontal cylindrical bore 41connects the outlet port 13 to the flow passage 35 at the intersectionof the bore 36 with its unaligned upper portion 37. A reducedcylindrical vertical bore 42, aligned with enlarged portion 38 of bore36, connects the flow passage 35 with the reduced bore portion 23 ofbore 26. An annular member 43, which defines a restricted flow port 44between the enlarged portion 38 and bore 36, is positioned in a circulargroove 45 in the enlarged portion 38, and the annular member 43 alsofunctions as a seat for a movable closure member, in the form of a ball46, having a diameter approximating, but slightly less than the diameterof the bore 36. The ball 46 is axially movable within bore 36 and closesport 15 when seated against the shoulder 47 between the enlarged portion37 of bore 36, and reduced bore 39, with the dimensions of the variousbores and the ball being coordinated so that horizontal bore 41 is notclosed by ball 46 when the ball 46 is seated against shoulder 47. Theball 46 may or may not be sealingly seated against the annular member43.

A flow passage 51 defined by a vertical cylindrical bore 52 having anunaligned enlarged upper portion 53 and an aligned enlarged lowerportion 54 is connected at its upper portion 53, with the vent port 14through reduced aligned bore 55. A horiztonal cylindrical bore 56connects the outlet port 12 to the flow passage 51 at the intersectionof the bore 52 with its unaligned upper portion 53. A cylindricalvertical bore 57, aligned with enlarged portion 54 of bore 52, connectsthe flow passage 51 with the reduced bore portion 27 of bore 26. Anannular member 58, which defines a restricted flow port 59vbetween theenlarged portion 54 and bore 52, is positioned in a circular groove 61in the enlarged portion 54, and the annular member 58 also functions asa seat for a movable closure member, in the form of a ball 62, having adiameter approximating but slightly less than the diameter of the bore52. The ball 62 is axially movable within bore 52 and closes port'14when seated against the shoulder 63 between the enlarged portion 53 ofbore 52 and reduced bore 55, with the dimensions of the various boresand the ball being coordinated so that horizontal bore 56 is not closedby ball 62 when the ball 62 is seated against shoulder 63. The ball 62may or may not besealingly seated against the annular member 58.

A rocker arm 71 is pivotally mounted to the valve body adjacent theports 14 and by a pivot pin 72, and the rocker arm 71 has downwardlyextending portions 73 and 74 which extend through the reduced bores 55and 39, respectively, into the enlarged portions 53 and 37 of bores 52and 36 respectively. The rocker arm 71 functions to prevent the balls 46and 63 from both being seated against their respective shoulders, ashereinafter described.

In operation, FIG. 1 depicts the valve without any flow of fluid throughthe inlet port 11 in which case the ball 31 is at rest seated against ashoulder 76 between bore 24 and bore 22; ball 46 is at rest in bore 36against annular member 43 placing ports 13 and 15 in fluid flowcommunication with each other through passage 35 and ball 62 ia at restin bore 52 against annular member 58 connecting ports 12 and 14 throughpassage 51. Upon the introduction of fluid into inlet port 11 (FIG. 2),the fluid flowing from inlet passage 16 through vertical bore 24 intobore 22 causes ball 31 to move upwardly in bore 22 and become seatedagainst shoulder 32 thereby preventing fluid from flowing to port 44,whereby the ball 46 in bore 36 remains at rest against annular port 43,maintaining fluid flow communication between outlet port 13 and ventport 15 through passage 35.

The fluid introduced through inlet port 11 flow through the bores 22 and26 and reduced bore 27 into the bore 52 through port 59 causing the ball62 positioned in bore 52 to move upwardly therein and become seatedagainst shoulder 63, thereby closing fluid flow communication betweenthe passage 51 and the port 14, and opening fluid flow communicationbetween the port 59 and port 12 through the passage 51. Thus, there is acontinuous passage of fluid from inlet port 11 to only outlet port 12.The seating of ball 62 against shoulder 63 pivots the rocker arm 71causing the portion 74 thereof to move further into the enlarged portion37 of bore 36 and thereby preventing the ball 46 from becoming seatedagainst shoulder 47. Thus, in the event that leakage of fluid past ball31 into reduced bore 23 and through port 44 causes ball 46 to moveupwardly in bore 36, the ball 46 can not close fluid flow communicationbetween ports 13 and 15 in that the ball 46 is not seated againstshoulder 47, and fluid can flow from port 13 between the ball 46 and thewall of the enlarged portion 37 to the vent port 15. Thus, as shown inFIG. 2, fluid flows through the valve from the inlet port 11 to theoutlet port 12, and fluid also flows between ports 13 and 15.

Upon stopping fluid flow through inlet port 11, the ball 31, seatedagainst shoulder 32, falls by gravity into bore 26 and rests thereinagainst a shoulder 77 formed between bores 26 and 28. The stopping offlow through port 59 causes ball 62 in bore 52 which was seated againstshoulder 63 to fall by gravity and come to rest against member 58. Thus,ports 12 and 14 are interconnected through passage 51 and ports 13 and15 are interconnected through passage 35, with balls 62 and 46 being atrest on annular members 58 and 43, respectively. Upon restartingintroduction of fluid into inlet port 11 (FIG. 3), the fluid flowingfrom inlet passage 16 through vertical bore 28 into bore 26 causes ball31 to move upwardly in bore 26 and become seated against shoulder 33,thereby preventing fluid from flowing through the reduced bore 27 toport 59, whereby the ball 62 in bore 52 remains at rest against annularmember 58, maintaining fluid flow communication between outlet port- 12and vent port 14 through passage 51.

The fluid introduced through inlet port 11 flows through the bores 22and 26 and reduced bore 23 into the bore 36 through port 44 causing theball 46 positioned in bore 36 to move upwardly therein and become seatedagainst shoulder 47, thereby closing fluid flow communication betweenthe passage 35 and the port 15, and opening fluid flow communicationbe-v tween the port 44 and the port 13. The seating of ball 46 againstshoulder 47 pivots the rocker arm-'71 causing the portion 73 thereof tomove further into the enlarged portion 53 of bore 52 and therebypreventing the ball 62 from becoming seated against shoulder 63. Thus,in the event that leakage of fluid past ball 31 into reduced bore 27 andthrough port 59 causes ball 62 to move upwardly in bore 52, the ball 62can not close fluid flow communication between ports 12 and 14 in i thatthe ball 62 is not seated against shoulder 63, and can flow from portbetween the ball 62 and the wall of the enlarged portion 53 to the ventport 14. Thus, as shown in FIG. 3, fluid flows through the valve fromthe inlet port 11 to the port 13, and fluid also flows between ports 12and 14 through passage 51.

Upon stopping fluid flow through inlet port 11 (FIG. 1), the ball 31,seated against shoulder 33, falls by gravity into bore 22 and reststherein against the shoulder 76 formed between bores 22 and 24. Thestopping of flow through port 44 causes ball 46 in bore 36 which wasseated against shoulder 47 to fall by gravity and come to rest againstmember 43. Thus, ports 12 and 14 areinterconnected through passage 51and ports 13 and 15 are interconnected through passage 35, with balls 46and 62 being at rest on annular members 43 I and 58, respectively.

The valve of the present invention is particularly suitable forcontrolling flow in a dual tower adsorption system and the use thereofin such a system is described with reference to an embodiment of such asystem illust'rated in FIG. 4. The embodiment is particularly describedwith reference to the de-hydration of air, but it is to be understoodthat the invention is equally applicable to fractionation, byadsorption, of other gaseous mixtures, as disclosed, for example, inU.S. Pat. No.

Referring to FIG. 4, the system for dehydrating a compressed gasincludes, as principal elements, a compressor 110, two drying chambers112 and 113 containing a suitable adsorbent, a storage tank or reservoir1 l4, and the four-way, five-ported valve 10 of the present'invention,having ports 11, 12, 13, 14 and 15, the ports Hand 15 functioning asexhaust ports and port 11 as an inlet port for a compressed gas. Thesystem, as illustrated in the drawing, is operating with drying beingeffected in chamber 112, and regeneration being effected in chamber 113,as represented by solid flow lines through valve 10. The broken flowlines through valve 10 is representative of the operation of the systemwith drying being effected in chamber 113 and regeneration beingeffected in chamber 112.

The compressor 110 is provided with a gas inlet coninlet for compressedwet gas during a drying portion of the cycle, and as an outlet forregenerating gas during a regeneration portion of the cycle. The upperportion of the drying chambers 112 and 113 are connected throughconduits 126 and 127, respectively, to the junction of conduits 128 and129 and conduits 131 and 129, respectively, the conduits 128 and 131being con nected to inlet ports 132 and 133, respectively, of a threeported, two position selector valve 134, and the conduit 129 including asuitable pressure reducing flow controller, preferably a fixed orifice,represented as 135. The conduits 126 and 127 function as an outlet fordehydrated compressed gas during the drying portion of a cycle and as aninlet for regeneration gas during the regeneration portion of the cycle,with the conduit 129 providing for the passage, as a regeneration gas,of a controlled amount of dehydrated gas from the drying chamberoperating on the drying portion of the cycle to the drying chamberoperating on the regeneration portion of the cycle.

The outlet port 136 of the selector valve 134, which is preferably, asshown, a ball type valve in which pressure at inlet port 132 moves theball thereof over to port 133 to cover and close same, and pressure atinlet port 133 moves the ball over to port 132 to cover and close same,is connected to the inlet of a reservoir or storage tank 114 throughconduit 137, including a check valve 138, and which is further providedwith a by-pass conduit 139 around check valve 138, the bypass conduit139 including a pressue reducing flow controller 141, preferably a fixedorifice as shown, and a valve 142. The reservoir or storage tank 114 isprovided with an outlet conduit 143, including a normally open valve144, to provide dehydrated compressed gas to asystem or appratus (notshown) employing dehydratedcompressed gas and is further provided with apressure sensitive switch, schematically represented as 145, of a typeknown in the art, which shuts the compressor on and off in response topreset minimum and maximum pressures, respectively, in storage tank 114.

In a typical operation, the pressure switch 145 is set to activate thecompressor 110 upon sensing a prede tennined minimum pressure inreservoir 114 (for example 25 psig), and to deactivate compressor 110upon sensing a predetermined maximum pressure in reservoir 114 (forexample 35 psig). Thus, for example, with a pressure of 30 lbs. inreservoir 114, the pressure control switch 145 has compressor 110 turnedoff and the air pressure in the system upstream of check valve 138 inconduit 137 is at about 0 psig, as a result of the upstream portionbeing open to the atmosphere by the direct connection of ports 12 and 13with vent ports 14 and 15, respectively.

Upon the pressure in reservoir 114 reaching the predetermined minimum,e.g., 25 psig, pressure switch 145 starts up compressor 110 wherebycompressed air flows from compressor 110 through conduit 122 into theinlet port 11 of valve 10 (the ball 31 being positioned as shown inFIG. 1) resulting in the valve being positioned as shown in FIG. 2.Accordingly, compressed gas flows from the inlet port 11 of valve 10 tothe outlet port 12 thereof and through conduit 124 into drying chamber112. The compressed gas passes through the absorbent in drying chamber112 thereby effecting drying of the compressed gas, and a major portionof the compressed gas withdrawn from drying chamber 112 flows throughconduits 126 and 128, ports 132 and 136 of selector valve 134 andconduit 137 into the reservoir 114. A minor portion of the air, the.amount of which is determined by the sizing of orifice 135 and theoperating pressure, flows through conduit 129 and is expanded throughthe orifice 135 for introduction into the drying chamber 1 13 throughconduit 127. The dry expanded gas flows through the adsorbent in dryingchamber 113 and readsorbs the water vapor adsorbed by the adsorbentduring a previous drying cycle. The gas, containing readsorbed water, iswithdrawn from chamber 113 through conduit 125 and is exhausted throughports 13 and of valve 10 (the valve being postioned as shown in FIG. 2).

The compressor 110 compresses more air than is withdrawn from reservoir114, and eventually the pressure in reservoir 114, is built-up to apressure above the predetermined maximum, i.e., 35 psig, at whichpressure, the pressure switch 145 shuts off compressor 1 10. Theshutting off of the compressor 111) stops the flow of gas through inletport 11 of valve 10, and as hereinabove described, the valve elementsare positioned so that the conduits 124 and 125 are connected to theatmosphere through ports 12 and 14 and ports 13 and 15, respectively, ofvalve 10. The pressure in the reservoir 114 is locked in by closing ofthe check valve 133 in conduit 137.

The cycle is again initiated upon the pressure reaching a predeterminedminimum in reservoir 1 14 with the flow of compressed air fromcompressor 110 to inlet port 11 of valve 10 resulting in the'valveelements being positioned as shown in FIG. 3. Accordingly, compressedgas flows from the inlet port 11 of valve 10 to the outlet port 13thereof and through conduit 125 into drying chamber 113. A major portionof the dried compressed air is passed to the storage tank 114 and aminor portion thereof is employed for regenerating the adsorbent inchamber 112 which is connected to the atmoshpere through conduit 124 andthe ports 12 and 14 of valve 10. Upon the pressure again reaching thepredetermined maximum in reservoir 1 14, the pressure switch 145 shutsoff compressor 110 and as hereinabove described the stopping of flow ofgas to inlet port 11 of valve 10 results in the valve elements thereofbeing positioned as illustrated in FIG. 1. A restarting of thecompressor 110 restarts the cycle, as hereinabove described. I

In some cases, in order to establish a desired dessicant dryness, overreactivation of the dessicant may be required. An excess regeneration ofthe dessicant may be achieved by opening valve 142 in by-pass conduit139 after the compressor 11'!) is shutdown, whereby a small amount ofair, as controlled by orifice 141 in bypass conduit 139, is passed fromreservoir 114 through by-pass conduit 139 and selector valve 134 to thechamber which has just completed the drying cycle and is now connectedfor the regeneration cycle upon reactivation of compressor 110. Ifdesired total regeneration or reactivation may be achieved by closingthe valve 144 in outlet conduit 143 whereby all of the air in reservoir114 may be returned through the drying chamber.

As should be apparent from the hereinabove description of a preferredembodiment of the invention illustrated in FIG. 4 each time thecompressor is activated,

one drying chamber is adsorbing water and the other is being desorbed ofwater, and each time the compressor is deactivated, the selector valveis automatically moved to a position in which upon reactivation of thecompressor the other drying chamber is in the drying portion of thecycle and the one drying chamber is in the reactivation portion of thecycle.

The present invention is an improvement over prior art dual towersystems in that a storage tank is provided downstream of the adsorptiontowers and the regeneration and adsorption cycles are controlled inresponse to compressor on-time. In this manner, regeneration is effectedonly during compressor on-time which is a function of the demand of theutilization system, resulting in the volume of gas employed forregeneration being proportional to the demand requirements of theutilization system. Moreover, the compressor operates at a fixed outputvolume of air, with the demands of the utilization system beingcontrolled by the on-time of the compressor and, therefore, the volumeof gas required for regeneration of the adsorbent is adjusted and fixedin relation to this volume, thereby eliminating the considerable wasteof gas which results in the prior art systems in which the regenerationgas requirements must be adjusted and fixed for the maximum load demandsof the utilization system. In addition, the use of the valve of theinvention alters the adsorption and desorption cycle by starting andstopping of fluid flow thereby eliminating the combination of timer andsolenoid valves employed in prior art systems.

These and other advantages should be apparent to those skilled in theart from the teachings herein.

The present invention may be modified in numerous ways within the spiritand scope of the invention. Thus, for example, although a five portedvalve has been particularly described, the present invention alsocontemplates a three ported valve in which fluid is alternately directedfrom an inlet port to one of two outlet ports. A three ported valvewhich incorporates the teachings of the present invention is illustratedin FIG. 5.

Referring to FIG. 5, a valve body 210 includes an inlet port 211, afirst outlet port 212 and a second out let port 213. An inlet passage216, defined by horizontal bore 217, extends inwardly through the valvebody 210 from the inlet port 211 and terminates within the valve body210.

A flow passage 221, defined by angular cylindrical bore 222 having anupper reduced portion 223, connected at its lower end to inlet passagd216 through a vertical cylindrical bore 224, extends angularly upwardlyaway from the inlet port 21 l, and a flow passage 225, defined byangular cylindrical bore 226 having an upper reduced portion 227,connected at its lower end to inlet passage 216 through a verticalcylindrical bore 228, longitudinally spaced from vertical bore 224,extends angularly upwardly toward the inlet port 211, with the bores 222and 226 intersecting at the upper ends thereof. The bores 222 and 226have identical diameters and a movable closure member, in the form of aball 23], having a diameter approximating, but slightly less than thediameter of the cylindrical bores 222 and 226, is movably positioned formovement within the bores 222 and 226 in response to fluid flowtherethrough to alternately seat against the shoulder 232 formed betweenbore 222 and its reduced portion 223, and the shoulder 233 formedbetween bore 226 and its reduced portion 227. The various dimensions ofthe bores 222 and 226 and the ball 231 are coordinated is seated againstshoulder 233, is positioned so that gravity causes the ball 231 to fallinto bore 222 upon stopping of fluid flow through the inlet port 211.

A flow passage in the form of horizontal cylindrical bore 241 connectsreduced bore 223 to the outlet port 213, and a flow passage in the formof horizontal cylindrical bore 242 connects reduced bore 227 to theoutlet port 212.

The operation of the embodiment of FIG. is similar to that of theembodiment of FIGS. 1 3. In operation, upon the introduction of fluidinto inlet port 221, the fluid flowing from the inlet passage 216through vertical bore 224 into bore 222 causes ball 231 to move upwardlyin bore 222 and become seated against shoulder 232 thereby preventingfluid from flowing to outlet port 213 and whereby fluid flows throughthe bores 222 and 226 and reduced bore 227 into the bore 242 and outletport 212.

Upon stopping fluid flow through inlet port 211, the ball 231, seatedagainst shoulder 232, falls by gravity into bore 226 and rests thereinagainst a shoulder 227 formed between bores 226 and 228. Upon restartingintroduction of fluid into inlet port 211, the fluid flowing from inletpassage 216 through vertical bore 228 into bore 226 causes ball 231 tomove upwardly in bore 226 and become seated against shoulder 233,thereby preventing fluid from flowing through the reduced bore 227 tooutlet port 2l2'whereby fluid flow through the bores 222 and 226 andreduced bore 223 into the bore 241 and outlet port 213. I

Upon stopping fluid flow through inlet port 211, the ball 231, seatedagainst shoulder 233, falls by gravity into bore 222 and rests thereinagainst the shoulder 276 formed between bores 222 and 224.

The hereinabove described embodiments and other embodiments are deemedto be within the scope of those skilled in the art from the teachingsherein.

Numerous modifications and variations of the present invention arepossible in light of the above teachings and, therefore, within thescope of the appended claims, the invention may be practiced in a mannerother than as particularly described.

What is claimed is:

1. A valve comprising: 1

a valve body including an inlet port, a first outlet port, a secondoutlet port, a first vent port, a second vent port;

first passage means withinthe valve body connected to said inlet port;second passage means within the valve body interconnecting the firstoutlet port and the first vent port, said second passage means beingconnected to the first passage means, said first and second passagemeans providing fluid flow communication between the inlet port and thefirst outlet port and between the first outlet port and the first ventport; third passage means within the valve body interconnecting thesecond passage means 4 within the valve body intersecting the secondoutlet port and the second vent port, said third passage means beingconnected to the first passage means to provide fluid flow communicationbetween the second vent port and the second outlet port and the inletport and the second outlet port; said flow control means comprisingfirst, second and third closure means; said first closure means beingwithin the first passage means movable by fluid introduced through saidinlet port to alternately close communication between the first passagemeans and the second passage means and the first passage means and thethird passage means in response to alternate starting of fluidintroduction into the inlet port; said second closure means beingpositioned in said second passage means movable by and in response toflow of fluid from the first passage means to the second passage means,said second closure means closing fluid flow communication between thefirst outlet port and the first vent port in response to fluid flow fromthe first passage means to the second passage means, whereby fluid ispassed from the inlet port to the first outlet port, said sec ondclosure means in response to no fluid flow from the first passage meansto the second passage means permitting fluid flow between the firstoutlet port and the first vent port; said third closure means beingpositioned in said third passage means movable by and in response toflow of fluid from the first passage means to the third passage means,said third closure means closing fluid flow communication between thesecond outlet port and the second vent port in response to fluid flowfrom the first passage means to the third passage means, whereby fluidis passed from the inlet port to the second outlet port, said thirdclosure means in response to no fluid flow from the first passage meansto the third passage means permitting fluid flow between the secondoutlet port and the second vent port.

2. The valve as defined in claim 1 wherein said first passage meanscomprises: a first bore having one end thereof connected to the inletport and the second end thereof connected to the second passage means,said second end of the first bore including a first seat; a second borehaving one end thereof connected to the inlet port and the second endthereof connected to the third passage means said second end of thesecond bore including a second seat, said first and second boresintersecting with each other adjacent their respective second ends; saidfirst closure means comprising a ball which is movable within andbetween the first and second bores, said ball when positioned within thefirst bore being moved into engagement with the first seat uponintroduction of fluid into the inlet port, said ball when positionedwithin the second bore being moved into engagement with the second seatupon introduction of fluid into the inlet port, the center of gravity ofthe ball when seated against the first seat causing the ball to fallinto the second bore upon stopping introduction of fluid into the inletport and the center of gravity of the ball when seated against thesecond seat causing the ball to fall into the first bore upon stoppingof introduction of fluid into the inlet port.

3. The valve as defined in claim 1 wherein said second closure meanscomprises a second ball movable within said second passage means, saidsecond passage means including a third seat for the second ball adjacentthe connection between the second passage means and the first bore, anda fourth seat for the second ball adjacent the connection between thesecond passage means and the first vent port, said second ball beingseated against the thirdseat upon stopping of fluid flow from the firstbore to the second passage means and said second ball being seatedagainst said fourth seat when fluid flows from the first bore to thesecond passage means.

0nd bore to the third passage means and said third ball being seatedagainst said sixth seat when fluid flows from the second bore to thethird passage means.

5. The valve as defined in claim 4 and further comprising means forpreventing the second ball and the third ball from simultaneously beingseated against the fourth and sixth seat, respectively.

1. A valve comprising: a valve body including an inlet port, a firstoutlet port, a second outlet port, a first vent port, a second ventport; first passage means within the valve body connected to said inletport; second passage means within the valve body interconnecting thefirst outlet port and the first vent port, said second passage meansbeing connected to the first passage means, said first and secondpassage means providing fluid flow communication between the inlet portand the first outlet port and between the first outlet port and thefirst vent port; third passage means within the valve bodyinterconnecting the second passage means within the valve bodyintersecting the second outlet port and the second vent port, said thirdpassage means being connected to the first passage means to providefluid flow communication between the second vent port and the secondoutlet port and the inlet port and the second outlet port; said flowcontrol means comprising first, second and third closure means; saidfirst closure means being within the first passage means movable byfluid introduced through said inlet port to alternately closecommunication between the first passage means and the second passagemeans and the first passage means and the third passage means inresponse to alternate starting of fluid introduction into the inletport; said second closure means being positioned in said second passagemeans movable by and in response to flow of fluid from the first passagemeans to the second passage means, said second closure means closingfluid flow communication between the first outlet port and the firstvent port in response to fluid flow from the first passage means to thesecond passage means, whereby fluid is passed from the inlet port to thefirst outlet port, said second closure means in response to no fluidflow from the first passage means to the second passage means permittingfluid flow between the first outlet port and the first vent port; saidthird closure means being positioned in said third passage means movableby and in response to flow of fluid from the first passage means to thethird passage means, said third closure means closing fluid flowcommunication between the second outlet port and the second vent port inresponse to fluid flow from the first passage means to the third passagemeans, whereby fluid is passed from the inlet port to the second outletport, said third closure means in response to no fluid flow from thefirst passage means to the third passage means permitting fluid flowbetween the second outlet port and the second vent port.
 2. The valve asdefined in claim 1 wherein said first passage means comprises: a firstbore having one end thereof connected to the inlet port and the secondend thereof connected to the second passage means, said second end ofthe first bore including a first seat; a second bore having one endthereof connected to the inlet port and the second end thereof connectedto the third passage means said second end of the second bore includinga second seat, said first and second bores intersecting with each otheradjacent their respective second ends; said first closure meanscomprising a ball which is movable within and between the first andsecond bores, said ball when positioned within the first bore beingmoved into engagement with the first seat upon introduction of fluidinto the inlet port, said ball when positioned within the second borebeing moved into engagement with the second seat upon introduction offluid into the inlet port, the center of gravity of the ball when seatedagainst the first seat causing the ball to fall into the second boreupon stopping introduction of fluid into the inlet port and the centerof gravity of the ball when seated against the second seat causing theball to fall into the first bore upon stopping of introduction of fluidinto the inlet port.
 3. The valve as defined in claim 1 wherein saidsecond closure means comprises a second ball movable within said secondpassage means, said second passage means including a third seat for thesecond ball adjacent the connection between the second passage means andthe first bore, and a fourth seat for the second ball adjacent theconnection between the second passage means and the first vent port,said second ball being seated against the third seat upon stopping offluid flow from the first bore to the second passage means and saidsecond ball being seated against said fourth seat when fluid flows fromthe first bore to the second passage means.
 4. The valve as defined inclaim 3 wherein said third closure means comprises a third ball movablewithin said third passage means, said third passage means including afifth seat for the third ball adjacent the connection between the thirdpassage means and the second bore, and a sixth seat for the third balladjacent the connection between the third passage means and the secondvent port, said third ball being seated against the fifth seat uponstopping of fluid flow from the second bore to the third passage meansand said third ball being seated against said sixth seat when fluidflows from the second bore to the third passage means.
 5. The valve asdefined in claim 4 and further comprising means for preventing thesecond ball and the third ball from simultaneously being seated againstthe fourth and sixth seat, respectively.